Electric power generation plants commonly bum some type of fossil fuel, e.g., natural gas, coal, fuel oil, etc., during the production of electricity. The flue gas resulting from the combustion of these fuel sources contains several compounds, including, but not limited to, nitrous oxides (“NOX”), carbon monoxide (“CO”), carbon dioxide (“CO2”), and oxygen (“O2”). It is important for operators to closely monitor the levels of these compounds in the flue gas stream to determine whether certain operating conditions should be changed. Accordingly, conventional systems exist that allow a sample to be taken from the flue gas stream and analyzed to determine the levels of certain compounds present in the gas. To ensure an accurate analysis of the flue gas as a whole, however, it is important to take samples from multiple points in the duct in which the flue gas is traveling because the detected levels can vary from point to point. By taking the readings from multiple locations in the duct, the operators can use statistical calculations, e.g., taking the average (possibly after excluding data point outliers, to obtain a clearer picture of the actual levels of compounds being emitted from the plant.
These conventional systems, however, operate in one of two ways. First, each system can use a probe at each location from which a data point will be taken to obtain a flue gas sample from that location. A sample from a first location can then be sent to a analyzer that measures the levels of certain compounds in the sample (e.g., as a percentage of the total sample size). Then, a sample from the next location is sent to the analyzer for detection of compound levels. This process is continually repeated by oscillating through each of the probes. Unfortunately, these samples cannot simultaneously monitor the levels at each probe location; rather, only one sample at a time from each location can be sent to the analyzer. The second types of systems can allow for simultaneous monitoring of levels at each probe, but require a separate analyzer to continually monitor each location, which leads to increases costs both from an equipment standpoint (e.g., multiple analyzers) and from a labor standpoint (e.g., labor for continually calibrating each of the analyzers).
Therefore, there is a desire for systems and methods that allow for the simultaneous testing of multiple samples from different locations in a more economical manner . Various embodiments of the present invention address these desires.